PORTLAND, Ore. — When you hear the sound of Y La Bamba, the musical experience sneaks up on you like the first few drops of a rainstorm. There's a steady drumbeat accompanied by ethereal guitar riffs ...

In Giro’s, a plushy nightspot in Mexico City, the band beat out a rumba rhythm. Americanos were on their feet almost before the Mexicans. Rotund Leon Henderson and his smartly tailored brunette wife, ...